Open, as in undecided, ambiguous, equivocal, unresolved, unsettled, unfinished; as in a question that has yet to be answered; as in existing as neither wholly one thing or the other, as an indeterminate entity suspended between mutually exclusive poles.

For 17 albums, The Necks — Chris Abrahams (piano), Tony Buck (drums), and Lloyd Swanton (bass) — have been sculpting music that is at once open to interpretation and and open in its dimensions. From the tranquilized swing of debut Sex (1995) through to the ex nihilo swells of Aether (2001) and the jittery paranoia of Chemist (2006), the Sydney trio lie somewhere in the fluctuating limbo between minimalism, jazz, and Krautrock, cultivating subtly extemporized arrangements that, in their often perforated and unhurried spaciousness, are as inclusive and incorporating of the silent, external, and non-musical as they are of their own proprietary, super-meticulous interplay of piano, bass, and drums. Now, as if they’ve decided both to distill this facet of their work into its purest expression and also to evolve beyond it, they’ve spawned Open, their first album for Brooklyn’s Northern Spy Records. Even though many of the familiar signatures are in place — the studied accretion of layers, the cavernous drifts of repetition, the scrupulous adherence to deceptively rich motifs — they’ve been put to a novel use for the latest 68-minute opus, namely one that has them engendering an all-pervasive tenor of uncertainty and creating large-scale pulsations of tension and release. And it’s this uncertainty, this monopolizing ambivalence as to where the piece will ultimately terminate, that permits the album to live up to its allusive name.

Previous deposits in the band’s library were similarly open-ended and improvisational in their overarching composition, but whereas a record like 1999’s Hanging Gardens fixed on an aggressive, very definite groove within a 16-bar form for pretty much its entire duration, Open is not only more segmented, but also more indefinite as far as the resonance and import of each particular segment is concerned, which arguably makes it a richer and more suggestive experience. The initial four minutes of the piece is one of several that feature the piano (or is it sometimes a guitar or harpsichord?) arrhythmically wavering and juddering on a cluster of single notes, gradually accompanied by splashes of percussion that only add to the insidiously jarring yet enticing sense of inconstancy. Here and throughout much of the album, The Necks sound as though they’re striving for a balance and repose that threatens never to come, the understated but no less unrelenting palpitations of their quiet dissonance implying that Open could itself be a representation of the impossibility of equilibrium/balance as such.

Open, as in exposed, unguarded, susceptible, vulnerable, assailable, fragile; as in accessible to foreign intrusion, to disruption and degradation; as in not forming a closed system that retains its original matter and integrity over time.

This rash speculation loses some of its implausibility during those passages where the keys of Chris Abrahams finally but all-too impermanently level themselves onto a more placid melody. This occurs at several junctures during the recording, and with each it momentarily seems as though the trio is about to stabilize on a theme and embellish it toward its natural ending. However, these transitory respites of serenity are always infiltrated by some alien element that dislodges them from their veneer of harmony, symmetry, and completion, be it such elements as the rise of electronic buzzing that transfigures the sedate ivory poise at the 20-minute mark or the lurking of echoed, disturbed ambience that undermines similar equanimity as the running time draws near to an hour. It might be supposed that this willful exposure amounts to a kind of self-sabotage on the part of The Necks, but the strategy in fact arguably emerges as Open’s most evocative and compelling element. This is because it both inflects each section with unexpected twists of depth, nuance, and concept, and also generates a palpable ambiguity and uneasiness that drives the entire album, an unpredictability that proves strangely addictive.

Moreover, it’s precisely because of the transience and mutability of Open as a whole that its fleeting moments of splendor prove all the more affecting and beautiful, despite the possible contention that — because of the often contradictory accompaniment — these might not be moments of splendor at all. When the final and most articulated chain of piano germinates at the very close of the piece, after numerous restive detours and absorbingly broken promises, the alleviation and relief is immediate and acute in its dispersion. For the first time in over an hour, all three members combine together to accentuate the same unsullied mood and direction, and as they fade out together, Open finally attains the imperturbable closure it had been seeking all along.